A work of extracting a selected foreground area, that is, a person or moving object area from an input real image sequence may be used for various purposes including a synthesis work of computer graphics (CG) and a real image, a 2D-to-3D conversion work of converting a 2D image sequence into a 3D stereoscopic image sequence, controlling a 3D effect for each object in a stereo 3D image, and the like.
As a method of extracting an area or a contour of an object from an image sequence in the related art, ‘active contour’, ‘gradient vector flow’, ‘graph-cut based image dividing scheme’, and the like have been studied, but since all the schemes depend on a luminance gradient or a color distribution in a boundary line area of the object, a flickering problem occurs and when a foreground and a background are similar in terms of color, a drift phenomenon significantly occurs around a boundary line.
In the case when the depth values of the foreground and the background are discontinuous and a photographing camera moves or a foreground object dynamically moves, background color information outside the boundary line is changed and as a result, a boundary line invasion problem, in other words, drift phenomenon occurs during tracking process. phenomenon of divided areas occurs while interframe tracking is performed.
Meanwhile, an automatic layer extraction function is provided even by commercial tools such as ‘After Effect’, ‘Mocha’ and the like which are used in a video content production industry, but a quality at a level utilizable in a company that produces a content for a movie theater is not provided, and thus associated companies still depend on a worker's manual labor.
Therefore, a method capable of suppressing a flickering phenomenon or a drift phenomenon and effectively extracting a foreground layer is required.